* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  height: 100vh;
  overflow: hidden;
  background: #f8f8f9;
}

.container {
  display: flex;
  flex-direction: column;
  height: 100%;
}

.panels-container {
  display: flex;
  height: 60vh;
  min-height: 80px;
  background: #fff;
}

.panel {
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  flex-basis: 0;
  min-width: 150px;
  background: #fff;
  overflow: hidden;
}

.panel-header {
  padding: 10px 15px;
  background: #17233d;
  color: white;
  font-weight: bold;
  font-size: 14px;
  user-select: none;
  flex-shrink: 0;
}

.editor-wrapper {
  display: flex;
  flex-grow: 1;
  overflow: hidden;
  background-color: #272822;
  font-size: 14px;
  line-height: 1.6;
}

.line-numbers {
  flex-shrink: 0;
  padding: 15px 10px;
  text-align: right;
  user-select: none;
  color: #8f908a;
  background-color: #272822;
  overflow: hidden;
  border-right: 1px solid #3a3b35;
}

.panel-content {
  flex-grow: 1;
  overflow: auto;
  border: none;
  outline: none;
  resize: none;
  background-color: transparent;
  color: #f8f8f2;
  font-size: inherit;
  line-height: inherit;
  padding: 15px;
  white-space: pre;
  caret-color: white;
}

.panel-content::placeholder {
  color: #6c757d;
  font-style: italic;
  opacity: 1;
}

.resizer-vertical {
  flex-basis: 6px;
  flex-shrink: 0;
  background: #f8f8f9;
  cursor: col-resize;
  transition: background 0.2s ease;
  z-index: 10;
}
.resizer-vertical:hover {
  background: #2d8cf0;
}

.resizer-horizontal {
  height: 6px;
  background: #f8f8f9;
  cursor: row-resize;
  transition: background 0.2s ease;
  z-index: 10;
  flex-shrink: 0;
}
.resizer-horizontal:hover {
  background: #2d8cf0;
}

.iframe-container {
  flex-grow: 1;
  min-height: 80px;
  background: #fff;
}

#previewFrame {
  width: 100%;
  height: 100%;
  border: none;
  background: #fff;
}

